Overloaded Consumer Units

[nozspark]

My idea, to make it all nice, neat and obvious is to; isolator supplies both rails, shift all non RCD circuits to top rail and move the RCD and all RCD circuits to bottom rail..

What do you think??

 

[JohnD]

the later Starbreaker with the prongs... you can't move the RCD. The busbar has a concealed division so you can only split it in one place

And the RCD has no screw-terminal for L in (or out)

 

[Adam_151]

Could probably squeeze a 12way split load in the place of that wylex standard?

Wouldn't worry about the showers too much, 100A board on 100A BS1361, but I suppose if you prefer, you could feed the second one from a separate RCD/MCB swithfuse down the bottom there (would try and install a second isolator as a single point of isolation though)

 

[nozspark]

John,
As you can tell this is the first time I have come across this type of CU and TBH I have some issues regarding the way that it has been wired, do you know if there is any way that the RCD can be moved to the bottom or is it an absolute no go? If that is the case then I'll have to try and get the RCD circuits up top!

 

[JohnD]

the shielded busbar with the slots in it,you might be able to take it out and fit it the other way round.That can helpif it is split e.g. 4/6, you can change it to 6/4.

I have worked on these before,but never had to do what you need. You can however get Starbreaker RCBOs. The early ones were two units wide, but the later onesare one unit. Might help.If ordering, take care to specify that you want the latest Starbreaker with prongs, the previous Starbreaker had ordinary screw terminals. I think the old part no's were like B32/610 and the new ones B32/61 but you'd better check.

Crabtree probably make busbars that you can order. Try calling their Hell Desk, they may have away. Double-decker CUs would be convenient if one rowwas RCD and one row not (you can easily do it on MEM 2000)

 

[plugwash]

what are the busbar arranagements like? i'd imagine you should be able to swap the RCD with the straight link without too much trouble.

 

[JohnD]

The busbar has an insulated cover with slots, that the "supply" terminal of MCBs and RCDs plugs in to. The load side is a screw terminal on the MCBs, but for the split-load RCD it is another prong, that plugs into a slot in the busbar cover. the two pieces of busbar are not connected inside the protective cover. So you can't position the RCd anywhere except over the point where the two halves of thge busbar are separated.

 

[nozspark]

Plug, it is as you see it in the photo. I have posted the picture in a larger size so you can see it better (hopefully)

 

[JohnD]

does this pic help?

 

[securespark]

HEY! THAT'S ROB'S JOB!!

 

[plugwash]

assuming they sell incomer RCDs i presume you could buy one and a shorter busbar and fit them on the bottom rail leaving the top rail alone.

or last resort option, make a hole in the side of the CU, fit a bushing to a two module box and put the RCD for the bottom rail in that.

 

[nozspark]

What I would like to do is move the RCD to the bottom rail adjacent to the through link and replace the busbars accordingly, but can you get the bits in the configuration that I want??

 

[plugwash]

i think you'd want a different RCD, one thats designed as an incomer RCD rather than a split RCD.

then you'd have to replace the busbars with ones the right size.

 

[nozspark]

As there are 2 spare MCB's and a space I think that I'll have to hope that there are only 3 circuits that need to be moved! Foiled again!!

Have a look at the board and see what else is wrong??

 

[JohnD]

HEY! THAT'S ROB'S JOB!!

I likepictures